Azure Storage Documentation

Understanding Azure Disk Performance Tiers

Azure Managed Disks offer a variety of performance tiers to meet diverse workload requirements, balancing cost and performance. This document outlines the different tiers available and provides guidance on selecting the most appropriate one for your needs.

Standard HDD

Standard HDD disks are the most cost-effective option, suitable for workloads that are not sensitive to performance. They offer consistent performance for applications like:

  • Web servers with low traffic
  • Backup and archive solutions
  • Development and test environments

Key Characteristics:

  • Low IOPS and throughput
  • Cost-effective
  • Asynchronous I/O

Standard SSD

Standard SSD disks provide a balance of cost and performance, making them ideal for workloads that require consistent latency and higher performance than HDDs. They are suitable for:

  • Web and application servers
  • Small to medium databases
  • Development and test environments requiring better performance

Key Characteristics:

  • Consistent IOPS and throughput
  • Improved latency over Standard HDD
  • Higher durability

Premium SSD

Premium SSD disks offer high-performance, low-latency disk storage. They are designed for mission-critical applications and production workloads that demand reliable performance. Suitable for:

  • Production databases (SQL Server, Oracle, MySQL, PostgreSQL)
  • High-performance web servers
  • Enterprise applications
  • Boot volumes for demanding VMs

Key Characteristics:

  • High IOPS and throughput
  • Low latency
  • Durable and reliable
  • Differentiated performance tiers (P1-P80)

Premium SSD Performance Tiers

Premium SSDs are further categorized into tiers (P1 to P80) based on their provisioned capacity, affecting their IOPS and throughput limits. Higher tiers offer greater performance.

Tier Max IOPS per disk Max Throughput (MB/s) per disk Max IOPS (cached) Max Throughput (cached) (MB/s)
P1 1,200 80 2,400 160
P2 2,400 160 4,800 320
P3 3,600 240 7,200 480
P4 7,200 480 14,400 960
P6 13,500 800 27,000 1,600
P10 22,500 900 45,000 1,800
P15 37,500 1,350 75,000 2,700
P20 50,000 1,750 100,000 3,500
P30 75,000 2,500 150,000 5,000
P40 120,000 3,500 240,000 7,000
P50 150,000 4,000 300,000 8,000
P60 200,000 4,500 400,000 9,000
P70 250,000 5,000 500,000 10,000
P80 300,000 5,500 600,000 11,000

Note: Caching is enabled by default for Premium SSDs and can significantly improve read performance. IOPS and throughput limits are per disk, not per VM.

Ultra Disk

Ultra Disk is the highest performance tier, offering configurable IOPS and throughput. It's designed for the most demanding, latency-sensitive workloads such as:

  • Top-tier transactional databases
  • High-performance computing (HPC)
  • Real-time analytics
  • Mission-critical applications with extreme performance needs

Key Characteristics:

  • Extremely high IOPS and throughput
  • Configurable performance
  • Lowest latency
  • Network attached storage

With Ultra Disk, you can independently provision storage capacity, IOPS, and throughput, providing granular control over performance characteristics and cost.

Performance Considerations

When choosing a disk tier, consider the following factors:

  • IOPS (Input/Output Operations Per Second): Measures how many read/write operations a disk can perform per second. Crucial for transactional workloads.
  • Throughput (MB/s): Measures the rate at which data can be read from or written to the disk. Important for large data transfers and sequential workloads.
  • Latency: The time it takes for a disk to respond to a read or write request. Critical for applications requiring quick responses.
  • Cost: Performance tiers have different pricing structures. Balance performance needs with budget constraints.
  • VM Size: The size and capabilities of your Virtual Machine also impact overall disk performance. Ensure your VM can support the disk's performance.
  • Caching: For Premium SSDs, host-based caching can boost read performance.

Choosing the Right Tier

Here's a general guide:

  • Standard HDD: For basic storage needs, development/testing, or archival.
  • Standard SSD: For general-purpose applications, web servers, and basic databases where consistency is important.
  • Premium SSD: For production databases, enterprise applications, and I/O-intensive workloads requiring consistent high performance and low latency.
  • Ultra Disk: For the most demanding, latency-sensitive, and high-throughput applications where configurable performance is paramount.

It is recommended to start with a tier that meets your minimum performance requirements and monitor your workload's performance. You can easily upgrade or downgrade disk tiers as needed to optimize cost and performance.